ligaments and joints of the upper limb - deranged … limb - 8 ligaments and... · ligaments and...

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Ligaments and Joints of the Upper Limb Sternoclavicular joint

Type of joint Saddle type synovial joint; but it functions like a

ball-and-socket joint ATYPICAL: fibrocartilage cover articular surfaces

Articulating surfaces Sternal facet of clavicle, clavicular facet of manubrium There is also an ARTICULAR DISC

Articular capsule Surrounds the joint, including the clavicular epiphysis Attached to the articular disc Lined with synovial membrane, contains synovial fluid

Ligaments Anterior and posterior sternoclavicular ligaments Interclavcular ligament Costoclavicular ligament

Stability factors Not many muscles around, and the surfaces are incongruous, so the joint relies on the ligaments for stability. Anterior and posterior sternoclavicular ligaments reinforce it anteriorly and posteriorly

Interclavicular ligament reinforces it superiorly Costoclavicular ligament reinforces it inferiorly Articular disc limits medial displacement

Movements Flexion, extension, rotation, anterior and posterior

movement, circumduction

Blood supply Internal thoracic and subscapular arteries

Nerve supply Nerve to subclavius Medial supraclavicular nerve

All joint stability depends on 3 factors: 1) shape of articulating surfaces; i.e. how

well the bones fit together 2) the ligaments 3) the tone of the surrounding muscles

Anterior sternoclavicular ligament

Costoclavicular ligament

Articular disc

Anterior sternoclavicular ligament

Articular disc: attached to the

anterior and posterior

sternoclavicular ligaments

Interclavicular ligament

Posterior sternoclavicular ligament


Acromioclavicular joint Type of joint Plane type synovial joint

Articulating surfaces Acromial end of the clavicle, and the acromion process of the scapula

Articular capsule Attached to the margins of the articular surfaces Lined with synovial membrane

Contains synovial fluid Strengthened superiorly by fibers from the trapezius

Ligaments Acromioclavicular ligament Conoid ligament Trapezoid ligament

Stability factors Stability is maintained by extrinsic ligaments, far from the joint itself Conoid and trapezoid ligaments anchor the clavicle to the coracoid process, suspending the free limb and scapula from the clavicle

Movements The acromian rotates on the clavicle

Blood supply Suprascapular and thoracoaromial arteries

Nerve supply Lateral pectoral and axillary nerve Subcutaneous lateral supraclavicular nerve

Conoid ligament

Trapezoid ligament

Coracoacromial ligament

Acromioclavicular ligament


Coracoclavicular joint Type of joint Not really much of a joint, as the two bones don’t really articulate. There is a rare anatomical abnormality when they actually come into contact, but normally the coracoid process attaches indirectly to the clavicle by means of the strong coracoclavicular ligaments, the conoid and the trapezoid.

Articulating surfaces Normally, none. The superior surface of the coracoid process attaches to the conoid and the trapezoid line of the clavicle by the ligaments abovementioned

Articular capsule No capsule

Ligaments Conoid ligament Trapezoid ligament

Stability factors Conoid and trapezoid ligaments anchor the clavicle to the coracoid process, suspending the free limb and scapula from the clavicle

Movements There is limited movement at this joint; the clavicle

rotates on the acromion.

Blood supply Suprascapular and thoracoaromial arteries

Nerve supply Lateral pectoral and axillary nerve

Subcutaneous lateral supraclavicular nerve


Glenohumeral joint Type of joint Ball and socket synovial joint

Articulating surfaces Humeral head articulates with the glenoid cavity. The cavity is deepened by the glenoid labrum. About 1/3rd of the head actually sits in the cavity.

Articular capsule Attaches proximally to the margins of the glenoid

cavity, and distally to the anatomical neck of the humerus. IT HAS HOLES IN IT. One hole admits the tendon of the long head of biceps brachii, and the other communicates with the subscapular bursa. THE WEAKEST PART is the inferior part which is not reinforced by the rotator cuff muscles

Ligaments Glenohumeral ligaments: intrinsic ligaments, three fibrous thickenings of the capsule, anteriorly

Coracohumeral ligament – from the base of coracoid to the anterior aspect of the greater tubercle Transverse humeral ligament- acts as the roof over the bicipital groove Coracoacromial ligament- forms the roof over the glenohumeral joint

Stability factors The joint is too shallow to be stable; stability is sacrificed to mobility The socket is deepened by the glenoid labrum

The joint is stabilized mainly by muscles: supraspinatus infraspinatus teres minor subscapularis

they hold the ball in the socket the coracoacromial arch and supraspinatus tendon limit superior displacement supraspinatus and teres minor limit posterior displacement subscapularis limits anterior displacement

Movements Greatest freedom of movement of any joint in the body Flexion/extension, abduction/adduction, medial and lateral rotation, circumduction

Assisted by the movement of the pectoral girdle (the scapula and the clavicle)

Blood supply Anterior and posterior circumflex humeral arteries Branches of the suprascapular artery

Capsule

Coracohumeral ligament

Transverse humeral ligament

Tendon of the long head of biceps

ligament


Nerve supply Suprascapular, axillary and lateral pectoral nerves

Factors Influencing the Stability of the Glenohumeral Joint MAINLY, THE ROTATOR CUFF: supraspinatus, infraspinatus, subscapularis and teres minor They hold the head of humerus in the glenoid fossa SOMEWHAT, THE LIGAMENTS: Glenohumeral

Coracohumeral Coracoacromial arch SLIGHTLY, THE GLENOID LABRUM

Supraspinatus

Subscapularis

Teres major

Latissimus dorsi

Pectoralis major

Bicipital groove

Supraspinatus

Infraspinatus

Teres minor

Teres major

Latissimus dorsi

Attachment for the lateral head of triceps


Elbow Joint

Type of joint typical synovial hinge joint

Articulating surfaces Trochlea of humerus articulates with the trochlear notch of the ulna Capitum of the humerus articulates with the head of radius the surfaces are most congruent when the arm is halfway pronated, and the elbow is flexed to a right angle

Articular capsule laterally and medially, just attaches to the margins of the articular surfaces

Anteriorly and posteriorly, the capsule comes up more proximally, to enclose the coronoid fossa and the olecranon fossa Distally, it blends with the capsule of the proximal radioulnar joint

Ligaments all are intrinsic- thickened parts of the joint capsule the lateral one is the Radial Collateral ligament - blends distally with the annular ligament of the radius; attaches to radial notch margins the medial one is the Ulnar Collateral ligament

- triangular, fan-like - the ANTERIOR band is the STRONGEST - the POSTERIOR band is the weakest - the slender and feeble OBLIQUE band merely serves to deepens the socket for the

trochlea of the humerus

Stability factors Major stability factor: bony alignment; The bones articulate well, the olecranon fossa limits hyperextension, and the coronoid fossa limits hyperflexion. The medial and lateral collateral ligaments serve to limit abduction and adduction- a minorstability factor

Movements It is PERMANENTLY ABDUCTED to 17 degrees: = The “carrying angle” = this angle is 10 degrees greater in women = it DISAPPEARS when the arm is PRONATED ..but the elbow only allows flexion and extension

FLEXORS: biceps brachii, brachialis, brachioradialis EXTENSORS: Triceps Brachii, Anconeus

o when the forearm is supinated, the biceps brachii helps flex it

o when the forearm is pronated, the pronator teres helps flex it. o major flexor is the brachialis; minor flexor is brachioradialis

Blood supply Derived from the anastomosis around the elbow joint

Nerve supply

Interosseous membrane

Anular ligament

Radial collateral ligament

Anular ligament Biceps tendon

Oblique cord

Interosseous membrane

Oblique band:

deepens the trochlear socket

Posterior band: weakest band

Anterior band: strongest, cord-like

The anular ligament attaches to the

margins of the radial notch

BURSAE: under every muscle attachment… the

most important are: - Intratendinous olecranon bursa sometimes

inside the tendon of the triceps - Subtendinous olecranon bursa between the

olecranon and the triceps tendon - Subcutaneous olecranon bursa in the

subcutaneous tissue over the olecranon


Musculocutaneous, ulnar and median nerve

Proximal Radioulnar Joint

Type of joint Pivot type synovial joint

Articulating surfaces The head of radius articulates with the radial notch of

the ulna

Articular capsule The fibrous part blends into the elbow joint The synovial part is continuous with the elbow joint

There is also a SACCIFORM RECESS of the joint, a distal extension of it down the radius which allows the radius to rotate without tearing the synovium

Ligaments The ANULAR ligament encircles the head of the radius

Stability factors The bones articulate well

The ANULAR ligament is the main stability factor, preventing dislocation of the radial head. The INTEROSSEOUS MEMBRANE also prevents distraction of the radius The joint is surrounded by muscles eg. brachioradialis and brachialis, which contribute to its stability in a minor way

Movements Pronation and supination Supination is the palm turning up, as if to receive alms The axis of rotation passes through the head of radius and through the site of attachment of of radius and ulna

distally THE RADIUS IS THE ONE THAT ROTATES

the ulna stays stationary

Blood supply Supplied by the radial portion of the periarticular arterial anastomosis of the elbow, which is the anastomosis of radial and middle collateral arteries with the radial and recurrent inteosseous arteries

Nerve supply Supplied by the musculocutaneous, median and radial

nerves, where pronation is work of the median supination is the work of the radial and

musculocutaneous nerves


Distal Radioulnar Joint

Type of joint Pivot type of synovial joint

Articulating surfaces The head of ulna articulates with the ulnar notch of the

medial distal radius which separates the the cavity of the distal radioulnar joint from the cavity of the wrist joint

Articular capsule The synovial membrane extends supeiorly between the radius and the ulna to form a SACCIFORM RECESS, which accommodates for the twistng of the capsule.

Ligaments Intrinsic ANTERIOR and POSTERIOR ligaments strengthen the joint capsule

These are weak transverse bands

Stability factors The ARTICULAR DISC is the main uniting structure of the joint, because it bings the ends of the radius and the ulna together

Movements During pronation, the radius crosses the ulna During supination, the radius is parallel with the ulna Supination is produced by Supinator Pronation is produced by the Pronator Quadratus …as well as Pronator Teres

FCR, PL and brachioradialis also help when the forearm is mid-pronated

Blood supply Anterior and posterior interosseous arteries

Nerve supply Anterior and posterior interosseous nerves

Articular disc

Ulnar styloid


Radiocarpal joint Type of joint Condyloid (ellipsoid) type of synovial joint

Articulating surfaces Three of the carpal bones (scaphoid, triquetrum and lunate) articulate with the radius The pisiform and the ulna don’t participate

Articular capsule Stretches from the distal ends of the radius and ulna, to the proximal row of carpal bones (but not the pisiform)

Ligaments The PALMAR radiocarpal ligaments stretch from the radius to both of the two rows of carpal bones; The DORSAL radiocarpal ligament does the same these ligaments make sure the hand follows the radius in its rotation the ULNAR COLLATERAL LIGAMENT passes from the ulnar styloid to the triquetrum the RADIAL COLLATERAL LIGAMENT passes from the radial styloid to the triquetrum

Stability factors The radius articulates tightly with the carpus; the styloid processes of the radius and ulna limit abduction and adduction

The ligaments and tendons supply most of the stability

Movements The movements of this joint are augmented by the slight movements permitted by the intercarpal and midcarpal joints. These are

flexion + extension (greater range of flexion than extension)

flexion is produced by FCR and FCU, Palmaris longus APL, Flexors of the fingers and thumb

extension is produced by ECRL, ECRB, and ECU Extensors of fingers and thumb

adduction + abduction (ulnar and radial deviation) – greater range of adduction(ulnar) than of abduction, because of the larger radial styloid. Most abduction occurs at the midcarpal joint.

Adduction is produced by Simultaneous ECU and FCU action

Abduction is produced by APL, FCR, ECRL and ECRB together

Circumduction – consists of successive flexion, adduction, extension and abduction

Blood supply: Branches of the dorsal and palmar carpal arch

Nerve supply: Anterior interosseous branch of the median nerve, posterior interossous branch of the radial nerve, and dorsal and deep branches of the ulnar nerve

Radial collateral ligament

Ulnarl

collateral

ligament

Articular disc

Palmar radiocarpal ligament Dorsal radiocarpall ligament


Intercarpal joints Type of joint Plane synocial joints

Articulating surfaces Joints between carpal bones of the middle row Joints between carpal bones of the distal row

MIDCARPAL JOINT: between the proximal and distal rows of the joints PISOTRIQUETRAL JOINT: articulation between the pisiform and the palmar surface of the triquetrum

Articular capsule The articular cavity is common to all intercarpal and carpometacarpal joints – EXCEPT the thumb, which has its own carpometacarpal capsule.

Ligaments All the carpals are united with anterior, posterior and interosseous ligaments

Stability factors The ligaments above contribute most;

The fibrous articular capsule wraps the carpal bones up, and keeps them together

Movements Slight movemens which extent the range of motion available at the radiocarpal joint

Blood supply Dorsal and palmar carpal arches

Nerve supply Anterior interosseous branch of the median nerve Dorsal and deep branches of the ulnar nerve


Carpometacarpal and Intermetacarpal joints Type of joint Plane type synovial joints- EXCEPT the carpometacarpal joint of the thumb, which is a saddle type joint

Articulating surfaces

Distal surfaces of the carpal bones articulate with the bases of the metacarpals The important thumb joint is the articulation between the trapezium and the bease of the first metacarpal The INTERMETACARPAL joints ar adjacent metacarpals articulating with each other’s bases

Articular capsule The medial four carpometacarpal joints, and the three intermetacarpal joints, are all enclosed by the same articular capsule. The thumb CMC joint has its own capsule

Ligaments All thse bones are united by the palmar and dorsal carpometacarpal ligaments, and by the intermetacarpal ligaments. The DEEP TRANSVERSE METACARPAL LIGAMENT and the SUPERFICIAL TRANSVERSE METACARPAL LIGAMENT (which is part of the palmar aponeurosis) both work to prevent separation of the metacarpal bases

Stability factors The above ligaments are he major stability factors

Movements Almost no movement at the CMCs of the 2nd and 3rd fingers, Slight movement at the 4th CMC Moderate movement of the 5th CMC (flexion, extension and rotation)

Blood supply

Periarticular arterial anasomoses of the wrist and hand (basically, the arterial arches)

Nerve supply Anterior interosseous branch of the median nerve, posterior interossous branch of the radial nerve, and dorsal and deep branches of the ulnar nerve

The carpometacarpal joint of the thumb is

independent – it has its own synovial

capsule


Joint at the base of the thumb: First carpometacarpal joint Type of joint Saddle-type synovial joint

Articulating surfaces Trapezium and the base of the 1st metacarpal

Articular capsule Coveres the articulating surfaces

Ligaments anterior oblique (volar) ligament (AOL)

dorsoradial ligament, posterior oblique ligament intermetacarpal ligament.

Stability factors Ligaments, mainly

Movements Angular movements in any plane: Flexion- extension Adduction-abduction (thus, circumduction) opposition

Blood supply Periarticular arterial anasomoses of the wrist and hand (basically, the arterial arches)

Nerve supply Anterior interosseous branch of the median nerve, posterior interossous branch of the radial nerve, and dorsal and deep branches of the ulnar nerve


Metacarpophalangeal and interphalangeal joints Type of joint Metacarpophalangeal joints are condyloid synovial joints

Interphalangeal joints are hinge joints Articulating surfaces Bases and heads

Articular capsule Joint capsules surround each joint, attaching to the margins

Ligaments Each MCP ad ICP joint is reinforced by a medial and lateral collateral ligaments Each of these ligaments has two parts: The dense cord-like part passes from one head to the next base; the thin fan-like part passes anteriorly to fuse with the anterior (palmar) part of the joint capsule

The cord-like parts are slack dring extension and taught during flexion- this means you usually cannot spread (abduct) the fingers when the fingers are fully flexed The fan-like parts move like a visor over the underlying heads The palmar ligament (thick part of the capsule) blend with the digital sheaths and provide grooves for the flexor tendons to glide in. At the MCPs, THE PALMAR LIGAMENTS ARE UNITED by the deep transverse metacarpal ligament Stability factors ligaments

Movements MCPS: flexion, extension, adduction, abduction

Blood supply Digital arteries

Nerve supply Digital nerves from the median and ulnar nerves

References: Moore’s Clinically Oriented Anatomy 5th

edition

ligaments and joints of the upper limb - deranged … limb - 8 ligaments and... · ligaments and...

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